Inter‐annual changes in prey fields trigger different foraging tactics in a large marine predator
Bibliographic record
Abstract
We report on inter‐annual comparisons of the foraging behavior of Global Positioning System–equipped chick‐rearing northern gannets ( Morus bassanus ) in the western Atlantic during years with contrasting oceanographic and prey conditions. We hypothesized that the predators would modify their foraging tactics when small fishes (capelin [ Mallotus villosus ]) and large pelagic fishes (mackerel, saury) varied in inter‐annual abundances. We predicted differences in (1) diving behavior, (2) spatial, and (3) temporal patterning of foraging behavior. Predictions 1 and 2 were supported, prediction 3 rejected. Dives were significantly deeper (4.3 ± 0.4 vs. 2.7 ± 0.3 m) and longer (10.1 ± 1.0 vs. 5.0 ± 0.2 s), and more U‐shaped dives (dives where birds stayed at more or less one depth) were performed (52% ± 7% vs. 7% ± 2%) in the year with higher abundance of forage fishes. Flight patterns exhibited remarkable spatial and geographic differences: gannets flew significantly (17%) more and foraging ranges were about twice as long when they pursued large pelagic fishes (mean = 122 ± 81 km vs. 62 ± 12 km). The 95% kernel feeding range was 34 times larger when large pelagic fishes were available. Yet foraging trip durations were not different between years. Inter‐annual variation in foraging tactics by the same species at the same colony in successive years was strongly related to prey availability, showing that spatial foraging parameters can be determined largely by ocean and prey conditions.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.001 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.003 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".